It is known in motor vehicles to provide a passive seat belt system in which an inertia operated seat belt retractor is mounted on the vehicle door for winding and unwinding a seat belt having its end mounted inboard the vehicle seat. Accordingly, when the door is closed, the seat belt is wound to a restraining position about the seated occupant. When the door is opened, the belt unwinds from the retractor and the swing geometry of the door establishes the belt outwardly and forwardly to enable occupant ingress and egress.
It has also been recognized as desirable to desensitize the door mounted inertia retractor upon opening of the vehicle door so that the inertia stimulus of door opening movement will not lock the retractor.
One preferred arrangement is disclosed in U.S. Pat. No. 4,598,932, Compeau et al, entitled Control Means For Occupant Restraint Belt System. The operation of either the inside handle or the outside handle temporarily desensitizes the inertia lock of the retractor. This desensitization is maintained, even if the inside or outside operator is released, by movement of the latch bolt toward its unlatched position during opening movement of the door. A sensor, such as a switch associated with the door latch, is electrically connected to a solenoid associated with the seat belt retractor. When the switch is closed by operating the inside or outside operator, or by movement of the latch bolt to the unlatched position, the solenoid is energized and operates a lever to desensitize the inertia sensor.
It would be desirable to provide a signal on the instrument panel to indicate to the occupant that the retractor inertia locking mechanism is temporarily desensitized.